Stylurus amnicola(Walsh, 1862)Riverine Clubtail

Status-Global/State:

Distinguishing Characteristics:

The males of most of the "hanging" clubtails (genus Stylurus) have long, slender abdomens. When perched on leaves, the bodies are pulled down by their weight, creating the appearance of "hanging" clubtails. The body length of the riverine clubtail varies from 1.8 to 1.9 inches. The pale markings on front of the thorax generally compose a 3-pointed star. On the sides of the thorax, a pair of wide stripes are angled slightly downward with a very narrow green shoulder stripe. The face is yellow-green with black lines and green eyes. The hind thighs are yellow. The male club has large yellow lateral spots with black lateral edges, near the end of the abdomen. The female is yellower than the male. The similar elusive clubtail differs in not having a frontal star and some other characteristics.

Description of Habitat/Range:

Found throughout northeastern United States and some states in the southeast, the riverine cubtail likes fast-moving medium to large rivers with sand, gravel, or mud bottoms. It is widespread throughout Wisconsin, although not in abundant numbers.

Flight Season:

In Wisconsin, adults have been documented from early June to early August.

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

58%(134)

34%(79)

7%(17)

1%(2)

<1%(1)

Shading illustrates monthly percentages of the total flight season records for the species.
Each flight season record is a unique date/location/observer combination where one or more adult or an
exuvia was recorded (excludes nymphs). The actual number of flight season records for each month is shown
in parentheses.

Flight seasons begin earlier in the southern
part of the state, often by a week or more. Also, flight charts may not be accurate for rare species because of
few data available.